Fix(contrib): knative manifest

[wg102]

Found while looking at upgrade 1.7
See #350 for original ticket

Configuration that should be looked over

In looking at the configmap of config-istio in knative-serving

In our kustomize patch we have

  gateway.ingress-general-system.general-istio-ingress-gateway-https: general.ingress-general-system.svc.cluster.local
  local-gateway.istio-system.cluster-local-gateway: cluster-local-gateway.istio-system.svc.cluster.local
  local-gateway.mesh: mesh

which is fine, but when I check the output I see an additional line (the second one)

  gateway.ingress-general-system.general-istio-ingress-gateway-https: general.ingress-general-system.svc.cluster.local
  gateway.kubeflow.kubeflow-gateway: istio-ingressgateway.istio-system.svc.cluster.local
  local-gateway.istio-system.cluster-local-gateway: cluster-local-gateway.istio-system.svc.cluster.local
  local-gateway.mesh: mesh

with the important bit being the gateway.kubeflow because I see in a comment a few lines above # This is commented out as we don't want it exposed on the gateway since the authenticaion only works for kubeflow.

Do note that this also still matches what we currently have on the cluster, but should be reviewed if we want this entry in the configmap